Twisting of the Heart May Predict Mitral Valve Surgery Outcomes
Assessing left ventricular torsion may help predict the outcome of mitral valve surgery in symptomatic patients with nonischemic, chronic secondary severe mitral regurgitation (NICSMR), according to a novel study published June 27 in JACC: Basic to Translational Science.
Yuichi Notomi, MD, and colleagues examined 50 consecutive symptomatic NICSMR patients for a median follow-up of 2.5 years after mitral surgery. All patients had advanced heart failure symptoms and had already received the maximum guideline-directed medical therapy for more than six months. Baseline left ventricular size, shape and mass tended to be larger and more spherical in those who died, but not significantly so, while left ventricular torsion was higher in survivors. Patients were divided into three groups: preserved left ventricular torsion, lost left ventricular torsion, or patients with a wide QRS measurement who received cardiac resynchronization therapy.
Patients received either mitral valve repair or mitral valve replacement. Two years after surgery, 19 patients had died. Researchers determined that in patients with NICSMR and a narrow QRS width, preserved left ventricular torsion may be a better predictor of post-mitral surgery survival, while conversely, lost left ventricular torsion may lead to a poor post-surgical outcome. The post-surgical survival results were intermediate in patients with a wide QRS. Patients who received cardiac resynchronization therapy prior to mitral surgery showed significantly worse two-year survival than those who received the procedure during mitral surgery. However, the two groups had similar left ventricular torsion.
The authors conclude that their study demonstrates that for patients with preserved left-ventricular torsion and a narrow QRS measurement, mitral surgery is an acceptable option and that left ventricular torsion can help to predict post-mitral surgery outcomes in patients with a narrow QRS but not in those with a wide QRS.
“Mechanistically, this study suggests that the loss of torsion in patients with heart failure may reflect irreversible structural damage to the heart which would prevent the heart from recovering after corrective surgery,” says Douglas L. Mann, MD, FACC, editor-in-chief of JACC: Basic to Translational Science. “If correct, this will have much broader implications than improvement after mitral valve surgery since it may predict which patients with heart failure may get better on medications.”
According to Mann, these findings will need confirmation as the analysis was retrospective and took place in a small number of patients. Kim A. Eagle, MD, MACC, editor-in-chief of ACC.org, agrees and notes that "with only data on 50 individuals, we need much larger data sets to see if this type of imaging could guide treatment."
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